Refrigerated cargo box

ABSTRACT

A refrigerated cargo box in which a generally rectangular pallet or base has a peripheral dovetail groove, the rear portion of which receives an outwardly directed curved tongue running along the bottom of a back panel having vertical sides and a trapezoidal top edge and the sides of which pallet receive inwardly directed tongues running along the bottoms of generally rectangular side panels. A dovetail groove running along the edge of the back panel above the bottom receives outwardly directed curved tongues of the side panels in its vertical portions, upwardly directed tongues along the backs of two slant panels in slant portions of the groove and a downwardly directed tongue of a top or keystone panel in the horizontal portion of the back panel groove. I provide releasably clamped gaskets along the mating edges of the tops of the side panels and the lower edges of the slant panels and along the edges of the keystone panel and the upper edges of the slant panel to give the box sufficient structural integrity as to do away with the need for external tiedowns to hold the parts together. The front of the pallet groove receives an outwardly directed tongue running along the bottom of a door and manually releasably clamping means on all of the front edges of the side panels, slant panels and top panel hold the door in position. Sealing means are provided at all joints. A self-contained refrigerating unit is carried by the keystone panel.

United States Patent [72] lnventor August G. Luisada Primary Examiner-Raphael H. Schwartz Waymart, Pa. Attorney-Shenier & OConnor go box in which a generally ase has a peripheral dovetail groove, the receives an outwardly directed curved he bottom of a back panel having trapezoidal top edge and the sides of which r a C d e t m t e .webhma mmfmb ranma u g Mmcmm nn @mmm .man nm Smfg man@ .fr t. n o .m TY l n $7 WN 90,-... 110k 80,0,Cm lzmv. oovlmrnmw eD. e .o/,FA N O. 6 N m ma I. n wmmm AHPA vertical sides and a [54] REFRIGERATED CARGO BOX 220/1 .5 panel.

,585 l/l934 France 60 256 j ser .all

INVENTOR 248 Hugu 6. Lu/'sada ZELE E ATTORNEY SHEU 1 0F 5 u lull". IMI" PATENTEU APR 20 |971 PATENTEU meolsn 3,'575312 SHEET 2 DFl 5 Haga/57 6. Lal/3nd@ ATTORNEYS PATENTEU m2201517:

SHEET 3 F 5 ATTORNEY 3 lNvEN-ron Hugus G Lu/sada #www ATTORNEYS PMWEU m20 1971 SHEU 5 UF nnrmolsnxrso canso nox BACKGROUND OF THE INVENTION Shipment of cargo by air, and particularly cargo which requires refrigeration during shipment, presents a number of difficulties. Owing to the irregular shape of the aircraft cargo space, much space is wasted by use of the ordinary cargo box. The cargo must be prevented from shifting during transit. Frozen comestibles such as ice cream and the like not only require insulation, but also they require refrigeration during shipment. Various proposals have been advanced for providing containers for air shipment of goods. The containers thus far proposed involve a number of defects. Most of them are relatively heavy. In order for them to withstand internal and external loads which may be encountered in use, they require external tiedowns over the top. They are either disposed of at the destination or require excessive deadhead storage space for return to the point of origin.

I have invented a refrigerated cargo container which overcomes the defects of cargo containers of the prior art. My cargo box has sufficient structural strength to withstand both internal and external loads incident to use without the need for external tiedowns extending over the top of the container. It is so shaped as to make maximum effective use of available aircraft cargo space. It is readily assembled and disassembled for repeated uses. Its parts may be shipped flat when disassembled to minimize deadhead space. It is flame-resistant, fireretardant, watertight, weatherproof and pilferproof. It is heat insulated and is provided with a self-contained refrigerating unit. It is light.

SUMMARY OF THE INVENTION One object of my invention is to provide a cargo box which makes maximum effective use of available cargo space in an aircraft.

Another object of my invention is to provide a refrigerated cargo box which overcomes the defects of cargo containers of the prior art.

A further object of my invention is to provide a refrigerated cargo box having sufficient structural strength to withstand both internal and external loads incident to its use without requiring external tiedowns extending over the box.

Still another object of my invention is to provide a refrigerated cargo box which can readily be disassembled to permit its parts to be shipped flat and then readily reassembled.

A still further object of my invention is to provide a refrigerated cargo box which effectively insulates its contents and which has a self-contained refrigeration unit.

Other and further objects of my invention will appear from the following description.

ln general my invention contemplates the provision of a refrigerated cargo box made up of a back panel, side panels, slant roof panels, a top or keystone panel and a door all formed of light insulating material and a pallet having a peripheral dovetail groove, the front and back of which receive outwardly directed curved tongues on the bottoms of the door and back panel and the sides of which receive inwardly directed tongues on the bottoms of the side panels. The back panel has a peripheral dovetail groove for receiving outwardly directed curved tongues on the backs of each of the side and slant panels and an inwardly directed tongue on the top panel. Scissors clamps provide watertight seals along the contiguous edges of the slant and side panels and contiguous edges of the slant and back panels provide watertight seals. Releasable clamping handles at the front edges of the panels clamp the door in place with a watertight seal. Insulating seals are located along all edges.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FIG. l is a perspective view of my refrigerated cargo box when it is completely assembled.

FIG. 2 is a fragmentary sectional view of the cargo box shown in FIG. l taken along the line 2-2 of FIG. 1 and drawn on an enlarged scale.

FIG. 3 is a fragmentary sectional view of the cargo box shown in FIG. l taken along the line 3-3 of FIG. l and drawn on an enlarged scale.

FIG. 4l is a fragmentary plan view of a corner ofthe pallet of my refrigerated cargo box.

FIG. 5 is a fragmentary sectional view of a portion of my refrigerated cargo box taken along the line 5-5 of FIG. l.

FIG. 6 is a fragmentary sectional view of the cargo box shown in FIG. l taken along the line 6-6 of FIG. 1 and drawn on an enlarged scale.

FIG. 7 is a fragmentary sectional view of my refrigerated cargo box taken along the line 77 of FIG. l and drawn on an enlarged scale.

FIG. 8 is a fragmentary sectional view of my refrigerated cargo box taken along the line 8-8 of FIG. 1 and drawn on an enlarged scale.

FIG. 9 is a perspective view of a simplified form of my cargo box.

FIG. 10 is a fragmentary sectional view of my cargo box taken along the line lll-l0 of FIG. 9 and drawn on an enlarged scale.

FIG. 11 is a fragmentary sectional view of the form of my cargo box illustrating FIG. 9 taken along the line 11-11 of FIG. 9 and drawn to an enlarged scale.

FIG. l2 is a fragmentary sectional view of the form of my cargo box illustrated in FIG. 9 taken along the line ll2-12 of FIG. 9 and drawn on an enlarged scale.

FIG. I3 is a fragmentary sectional view of the form of my cargo box illustrated in FIG. 9 taken along the line 13l3 of FIG. 9 and drawn on an enlarged scale.

FIG. I4 is a sectional view illustrating a still further form of panel connecting means which I may employ in my cargo box.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, my refrigerated cargo box, indicated generally by the reference character l0, comprises a base or pallet, indicated generally by the reference character l2, side panels, one of which indicated generally by the reference character I4 is shown in the drawings, a back panel indicated generally by the reference character I6, respective slant roof panels indicated generally by the reference character I8 in the drawings, and a top panel indicated generally by the reference character 20. As will be explained more fully hereinafter, these parts are adapted to be assembled to form the box l0.

Referring to FIGS. l to d, the pallet l2 includes a front edge extrusion 22 formed of aluminum or the like and a similar back extrusion 28, as well as respective side extrusions 24 and 26. While the respective front and back extrusions may be of different lengths than are the side extrusions 24 and 26, owing to the fact that all the extrusions are in other respects generally identical, only the front extrusion 22 will be described in detail. The extrusion 22 includes a top flange 29 formed with a longitudinally extending dovetail groove 30 and a bottom flange 32. l provide the edge of the extrusion with a step M which facilitates the application of the means for holding the box l0 in position on a carrier. The ends of the respective extrusions are beveled so as to provide a plurality of joints 3o at the comers of the pallet. In order to hold the extrusions firmly in assembled relationship, portions of the corners are cut out to receive comer pieces 38 having flanges t0 which are secured to the respective extrusions by any suitable means such as by aluminum blind rivets 42. y

The stmcture thus far described makes up the pallet frame. The central portion of the pallet surrounded by the frame includes a body 44 of 2-inch thickness formed from 5 pounds per cubic foot polyurethane foam having a K factor of about 0.25. l provide the body 44 with a bottom skin 46 which may be made of 0.036-inch thick aluminum sheet secured to the bottom flanges of the edge extrusions by any suitable means, such as by aluminum blind rivets 48. Preferably l form the upper skin 50 of the pallet l2 from a material such as 0.040- inch thick fiber glass-epoxy resin laminate. Blind rivets 52 may be provided to secure the upper skins 50 to the flanges 29 of the pallet edge extrusions.

Referring to FIG. 2, the side panel 14, as well as the other side panel, is made up of a central body 54 of 2-inch thick 2.65 pounds per cubic foot polyurethane foam having a K factor of about 0.14. l provide the side panel 14 with respective outer and inner skins 56 and 58, each of which is made up of 0.040 fiber glass-epoxy resin laminate. The upper and lower edges of the panel 14 carry respective frame members 60 and 62, each of which is made up of any suitable material such as 0.025- inch thick aluminum sheet. The construction is such that the frame members 60 and 62 overlap the edges of the skins 56 and 58 for a short distance.

l secure an extrusion 64 of aluminum or the like forming a curved, inwardly directed, elongated tongue 66 to the lower frame member 62. As will be explained more fully hereinafter, when the side panels, such as the panel 14, are assembled on the pallet l2, the tongue 66 enters into the dovetail groove 30 in the pallet side extrusion 24. The tongue in the other panel which is not shown similarly enters the dovetail groove 30 in the extrusion 26.

l provide the lower edge of the side panel 14 with a heat seal, indicated generally by the reference character 68, extending along the frame 62. Seal 68 may for example comprise a vinyl plastic cover 70 filled with a suitable material such as pounds per cubic foot acrylonitrile foam 72 having a l( factor of about 0.2. lt will be seen that l provide the frame 62 with an inclined portion 74 which causes the seal 68 to be squeezed between that portion of the pallet as the side panel is erected, thus to ensure a good heat seal along the lower edge of the panel 14.

l secure an extrusion 76 forming an outwardly opening groove 78 having an outer wall 80 with a transverse sinuous cross-sectional shape to the upper frame member 60 by any suitable means such as by welding or the like. A heat seal, indicated generally by the reference character 82, comprises an envelope 84 of a suitable material such as a vinyl plastic housing insulating material such as acrylonitrile foam 86. l provide the envelope with an extension 88 which is sandwiched between frame 60 and the channel-forming portion of extrusion 76. As will be explained more fully hereinafter, when the box is assembled the seal 82 provides a heat seal between the side panel 14 and a portion of the top of the box.

Referring to FIG. 6, the back edge of the panel 14 carries a frame portion 90 of the same material as are the frame members 60 and 62. l weld or otherwise secure an extrusion 92 fonning an outwardly directed curved tongue 94 to the frame portion 90 to form a connection with the back panel in a manner to be described. The construction of the front edge of the side panel 14 will be apparent from the description hereinafter of another member of my refrigerated cargo box. Since the other side 14 of the box is substantially identical to the side panel 14, it will not be described in detail.

Referring to F10. 3, the back panel 16 of my cargo box includes a central body 96 having inner and outer skins 98 and 100 which are similar in construction to the body and skins of the side panels, such as panel 14. The lower edge of the back panel 16 carries a frame 102 formed from sheet aluminum such as that which is used to form frame members 74 and 88. I weld an extmsion 104 formed with an outwardly directed tongue 106 to the frame 102. As will be explained more fully hereinafter, tongue 106 enters into the dovetail groove 30 of the rear or back pallet extrusion 28 when the back panel 16 is erected. Any suitable bonding agent such, for example, as an epoxy resin or the like, secures a vinyl plastic envelope 108 to the frame member 102. Envelope 108 contains expanded acrylonitrile foam 110 to provide a heat seal between the lower edge of the back panel 16 and the pallet.

Referring to FIGS. 3 and 6, the edges of the back panel 16 other than the bottom edge carry a sheet aluminum frame member 112 which extends over the edge of the back panel above the bottom thereof. l weld or otherwise secure a casting 114 having the same configuration as the frame member 112 over the frame member. The casting 114 is provided with a dovetail groove 116 for receiving tongues, to be described hereinafter, on the top panel 20, on the slant panels 18 and on the side panels of the box. l provide the back panel with a seal, indicated generally by the reference character 118, extending around the back panel 16 above the bottom thereof. Seal 118 comprises an envelope 120 of vinyl plastic housing expanded acrylonitrile resin 122. An extension 124 or'i the envelope is sandwiched between the groove-forming part of the extrusion 114 and the frame 112. l may also use a suitable bonding agent, such as an epoxy, to hold seal 118 in place on the back panel.

The outwardly directed curved tongues 94 along the back edges of the side panels enter into the groove 116 in the vertically extending portions of the casting 114 as the side panels 14 are erected in a manner to be described.

Referring to FIG. 5 the slant panels 18 of my refrigerated cargo box comprise central body portions 128 and outer and inner skins 130 and 132 which are similar in construction to the body 54 and the skins 56 and 58. The rear edge of each of the slant panels carries an aluminum sheet frame 134 extending along the rear edge of the panel 18. l weld or otherwise secure an aluminum extrusion 136 to the upper portion of the frame member 134. Extrusion 136 is formed with an upwardly directed tongue 138 which is adapted to engage in the dovetail groove 116 in one of the slanting portions of the extrusion 114.

Referring again to FlG, 2, a frame member 140 of sheet aluminum or the like extends along the lower edge of each slant panel 18. l weld an extrusion 142 to the outer portion of the frame 140. Extrusion 142 provides an inwardly directed flange or tongue 144 which is spaced a short distance away from the lower edge of the panel 18. When the slant panel 18 is assembled with the other parts of the box in a manner to be described, tongue 144 cooperates with the upper wall 80 of the channel 78 to form respective pockets which receive gaskets 146 and 148 formed of any suitable material such as natural or artificial rubber to clamp the side panel to the slant panel with what may be termed a scissors action.

l weld or otherwise secure another extrusion 150 providing an inwardly directed tongue 152 to an aluminum sheet frame member 154 extending along the upper edge of the slant panel. Tongue 152 has a sinuous transverse cross-sectional shape to form gasket-receiving pockets in a manner to be described. The front edge of each of the slant panels 18 carries a portion of the door-locking mechanism to be described hereinafter.

Referring to FIGS. 2 and 3, the top panel 20 of my refrigerated cargo box includes a central body 156 having skins 158 and 160. The body 156 and the skins 158 and 160 may be formed of the same material as are the body 54 and the skins 56 and 58. A sheet aluminum frame member 162 extending along the rear edge of the top panel 20 carries an aluminum extrusion 164 formed with a downwardly extending tongue 166 adapted to enter into the horizontal portion of the dovetail groove 116 when the box is assembled in a manner to be described. The front edge of the top panel 20 carries an aluminum extrusion 168 formed with a socket or journal 170 for rotatably receiving the shaft 172 of a locking lever 174 having a handle portion 176 formed with an inner cam surface 178. The forward edges of the side panels 14 and the forward edges of each of the slant panels 18 carry handles 180, 182, 184 and 186 similar to the handle 176. Since these handles and their associated structures are substantially identical to that of the handle 176 and its associated structure, they will not be described in detail. Each of these structures includes a recess or groove 188 in the extrusion 168 for receiving a gasket 188. Moreover, I provide a seal comprising a vinyl plastic envelope 192 and a body of expanded acrylonitrile foam 194 extending around the sides, the slant panels and the top panel at the front of the box.

Referring again to FIG. 2, l weld or otherwise secure an extrusion 256 to sheet aluminum frame portions 258 extending along the sides of the top panel 20. The extrusions 56 form generally U-shaped channels 260 having outer walls 262 of undulant cross section. This channel 260 cooperates with the tongue 152 when the box is assembled to clamp gaskets 264 and 266 between the tongues 152 and the walls 262. A seal, indicated generally by the reference character 268, has an envelope 270 formed of vinyl plastic or the like containing a filler 272 of expanded acrylonitrile resin. An extension 274 of the envelope is sandwiched between the inner wall and channel 260 and the frame 258.

Referring to FIGS. 1 and 3, the door, indicated generally by the reference character 196, comprises a central body 198 of expanded urethane foam and glass epoxy outer and inner skins 288 and 282 which are similar to thebody 54 and the skins 56 and 58 for example. The lower edge of the door 196 carries a sheet aluminum frame 204 to which l weld an aluminum extrusion 286 formed with an outwardly directed tongue 208 which is inserted in the dovetail groove 30 in the frontextrusion 22 of the pallet when the box is assembled. A seal, indicated generally by the reference character 210, comprising an envelope 212 of vinyl or the like and an expanded acrylonitrile filler 214, is secured to the inside of the door 196 along the lower edge thereof. When the door is in position, seal 218 engages the upper surface of the pallet along the bottom of the door.

The horizontal upper edge of the door 196 carries an extrusion 216 formed with a flange 218 providing a cam surface 2211 which cooperates with the cam surface 178 when the door is locked in a manner to be described. An inner recess 222 in the extrusion 216 receives a gket 224 adapted to cooperate with the top panel 20. An extension 226 on the extrusion also engages the gasket 190 when the door is closed. It is to be understood that the casting 216 and the parts thereof which have just been described extend all along the rear of the door except along the bottom edge thereof. This extrusion may of course be formed in sections for ease in manufacture. l also provide a seal, indicated generally by the reference character 228, comprising a vinyl envelope 230 and an expanded acrylonitrile filler 232 extending around the inside of the door except along the lower edge thereof. This seal may be secured in position by any suitable means such, for example, as by an epoxy resin or the like.

Referring to FIGS. 1, 7 and 8, I provide my refrigerated cargo box with a refrigeration unit, indicated generally by the reference character 234, secured to the top panel 20 by any suitable means such as by bolts 236 or the like. The unit 234 includes a housing 238 containing the refrigerating coils 240 as well as a compressor and fan (not shown). Return air from the interior of the box 10 flows into the housing 238 through the opening 242 past the portions of the coils in which the refrigerant is permitted to expand and through an opening 244 to a cold air outlet duct 246 provided with outlet louvers 248. Cooling air from the outside is admitted to the unit through an opening in the upper panel 28. This air passes by the portions of the coils containing compressed refrigerant and thence outwardly through an outlet 252. Suitable controls 254 are provided. l provide the top 28 with a breather or pressure equalizer 256 comprising a ller of fiberglass and top and bottom closures 268 and 262 of gas-permeable, waterimpermeable cloth. Since the particular refrigerating unit does not itself form a part of my invention, it will not be described in greater detail.

While my cargo box does not require any external u'edowns extending over the box to absorb internal loads, l provide the sides 14 with a plurality of tiedown fittings 264 carried by plates 266 secured to the inner surface of the sidewalls. These fittings may receive suitable lines or the like or even a net to hold the cargo in position on the pallet.

In order to assemble the box the back panel 16 is raised by inserting its tongue 106 in the groove 30 with the panel sloped rearwardly and then rotating it to an erect position. Next, the side panels 14 are erected by inserting their tongues 66 in the groove 30 with the panels sloped slightly inwardly and then by moving the panel to an erect position. In the course of this operation the tongues 94 ride into the vertical portions of grooves 116. When that has been done, the slant panels 18 are erected by inserting their tongues 138 in the corresponding slant portions of groove 116 and moving them downwardly. In the course of that action, the tongue 144 moves into the channel 78 and the gaskets 146 and 148 are clamped in position. The last step in assembling the box before it is loaded is to position the top or keystone panel 28 in position. This is done from the inside by inserting the tongue 166 in the horizontal portion of groove 116 and then rotating the keystone panel 28 upwardly. As that occurs, the tongue 152 enters the channel 260 and the gaskets 264 and 266 are clamped in position. The action of the top panel 20 is similar to that of the keystone of an arch with the exception that once it has been erected, the construction affords as much resistance to internal loading as to external loading.

With the box thus far erected, the box is now ready to receive cargo. After it has been loaded, all of the handles 180, 182, 176, 184 and 186 are moved to open positions. The tongue 208 on the door then is inserted in groove 30 of extrusion 22 and the door is swung upwardly over the front of the box. Next, all of the handles are moved to closed positions to cause the surfaces 178 and 228 to cooperate to clamp the cover in place while providing an insulating seal all around the joints of the various parts of the box.

It will readily be appreciated that upon arrival at its destination, the box may easily be disassembled to permit removal of its contents. The various members of which the box is formed can be stored and shipped flat and can readily be reassembled for another use.

Referring now to FIGS. 9 to 18, I have shown a simplified form of my cargo box which is simpler and which is less expensive to construct than is the form of the box illustrated in FIGS. 1 to 8. In the form of my invention illustrated in FIGS. 9 to 13 as will be apparent from the description hereinafter, rather than extruding the means for connecting the various parts of the box, I form these connecting elements from sheet metal. Since the bodies of the various parts of the box illustrated in FIGS. 9 to 13 are the same as those of FIGS. 1 to 8, l have employed the same reference characters to designate the panel bodies as are used in FIGS. 1 to 8.

While the base 12 of the form of the invention illustrated in FIGS. 9 to 13 includes the body 44 having skins 46 and 50, rather than employing the extrusion 24 I simply provide the perimeter of the base with a peripheral frame 268 of sheet aluminum or the like which serves to reinforce the base and to make it an integral unit. I weld or otherwise secure a tongue and channel forming member 270 shaped like an angle iron to the periphery of the member 268 with a flange 272 of the member 278 slightly spaced from the upper surface of the base to form a groove which receives a sealing gasket 274.

Further in this form of my invention, rather than attaching an extrusion such as the extrusion 64 to the side panel bottom cap 62, I weld or otherwise secure a tongue and groove forming member 276 to the cap 62 with a flange 278 on member 276 spaced from the bottom of the panel 14 so as to receive a gasket 288. It will readily be understood that the members 278 and 276 are easily formed from a length of sheet metal such as sheet aluminum. When the box is erected, the flanges 272 and 278 are slid into the grooves formed by the flanges 274 and 272 so that flange 278 engages gasket 274 while 272 engages gasket 280 to provide a double seal. This connecting arrangement may be employed all around the periphery of the base 12.

In joining the slant roof panels 18 to the back panel 16 I secure a sheet metal receptacle or keeper 282 to the frame 112 of back panel 16. The upper portion 284 of the keeper 282 is bent through an arc of about 135. I secure a keeper engaging member 286 to the underside of the frame 134 of the slant panel 18. This keeper engaging member 286 has an arcuate bent portion 288 which preferably is bent to an angle of about 225. The space between the terminus of the bent portion 284 and the edge of panel 16 permits entry of member 288 when panel 18 is generally parallel to panel 16 as indicated by broken lines in FIG. 11. When that has been done, the panel is swung downwardly and forwardly in the direction of the broken arrow A until the portion of member 286 running from the bent portion 288 to the frame 134 comes to rest on top of frame 112. When that has been done, the side panel is erected and keeper 282 retains portion 288 of member 286. 1t may readily be removed by reversing that sequence of operations.

The coupling for mounting the top panel on the back panel 16 includes a keeper 290 secured to the frame 112 at the horizontal top portion thereof. l provide keeper 290 with a bent portion 292 extending through an arc of about 225. A keeper engaging member 294 is secured to the back edge of the top panel frame 162. This keeper engaging element 294 has a bent portion 296 extending over an arc of about 225. ln erecting the top panel after the slant roof panels have been erected in the manner described hereinabove with the top panel 20 extending generally vertically downwardly, the keeper engaging member 296 can be inserted into the portion 292. From that position, the panel can be swung in the direction of the arrow B in FIG. 12 until it reaches its fully erected position in which portion 292 retains portion 296.

In the form of my cargo box illustrated in FIGS. 9 to 13, I employ a somewhat simplified arrangement for holding the edges of the panels respectively to the top panel 20 and to the side panel 14. l secure a tongue and groove forming member 298 to the top frame 60 of a side panel with flange 300 in spaced relationship to the upper edge of the side panel to form a groove for receiving a gasket 302. l secure a similar tongue and groove forming member 304 to the frame 140 of the side panel with a flange 306 spaced from the lower edge of the slant panel to form a groove for receiving a gasket 308. As the side panels are erected in the manner described above, the respective flanges 380 and 306 engage gaskets 308 and 302. I may employ a similar connecting means for joining the edges of the slant panels to the edges of the top panel.

Referring to FIG. 14 in a further form of connecting means for joining a slant roof panel 18 to the back panel 16, for example, a keeper 310 formed with an arcuate portion 312 is welded or otherwise secured to frame 112. The portion 312 receives and retains an arcuately bent back portion 316 of an intermediate element 314 provided with a flange 318 which receives a curved portion 322 of a connector 320 secured to frame 134 by welding or the like. The manner in which the slant root` panel 18 is secured to back panel 16 with this form of my connecting means will be apparent from the description hereinabove.

While I have described the form of my cargo box illustrated in FIGS. 1 to 9 as being a refrigerated box, it will readily be understood that the construction is of general application. For that reason, I have not shown that the panels are formed of insulating material in FIGS. 9 to 13, and I have eliminated the thermal seals from this form of my box.

It will be seen that l have accomplished the objects of my invention. I have provided a refrigerated cargo box especially adapted for air shipment of frozen comestibles. My box overcomes the defects of cargo containers of the prior art. 1t has sufficient structural strength to withstand both internal and external loads incident to its use without the necessity of external tiedowns extending over the top of the box. 1t may readily be disassembled, the parts thereof shipped flat and then reassembled for repeated uses. lt is flame-resistant, fireretardant and watertight.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of my claims. lt is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

Iclaim:

1. A readily disassembled cargo box including in combination, a base having a rectangular configuration, a back panel having a rectangular lower portion and a generally trapezoidal upper portion, respective rectangular side panels, respective rectangular slant roof panels, a rectangular central roof panel, a door having a rectangular lower portion and a trapezoidal upper portion and readily releasable means for connecting said back and side panels and said roof panels and said door to fon'n said box, said releasable means comprising means forming respective clamping means along adjacent edges of said top panel and of said slant panels, said clamping means adapted to engage in response to swinging movement of said top panel about its back edge.

2. A cargo box as in claim 1 in which said panels and said door are formed of insulating material.

3. A cargo box as in claim l in which said releasable means comprises interengageable means running along the bottoms of said side panels and along the corresponding edges of said base, said interengageable means comprising dovetail grooves and tongues located in said grooves.

4. A cargo box as in claim 3 in which said dovetail grooves are in said base and in which said tongues are inwardly directed tongues on the bottoms of said side panels.

5. A cargo box as in claim 1 in which said readily releasable means comprise interengageable means running along the bottom of said back panel and said door and along corresponding edges of said base, said interengageable means comprising dovetail grooves and tongues located in said grooves.

6. A cargo box as in claim 5 in which said dovetail grooves are in said base and wherein said tongues are outwardly directed tongues on said back panel and door.

7. A cargo box as in claim 1 in which said readily releasable means comprises means forming a dovetail groove in the upper surface of said base running around the periphery thereof, respective inwardly directed tongues along the bottom edges of said side panels located in corresponding portions of said groove and respective outwardly directed tongues along the bottom edges of said back panel and said door.

8. A cargo box as in claim 1 in which said releasable means comprises interengageable tongue and groove forming means along the rear edges of said side panels and along the vertical edges of said back panel.

9. A cargo box as in claim 1 in which said releasable means comprises means forming a dovetail groove adjacent the upper edge of said back panel, respective upwardly directed tongues along the edges of said slant panel located in said groove and a downwardly directed tongue at the rear edge of said central top panel, said tongues located in said grooves.

10. A cargo box as in claim 1 in which said releasable means comprises clamping means extending along adjacent edges of the side panels and slant roof panels.

11. A cargo box as in claim 10 in which said clamping means comprises means forming outwardly opening channels along the upper edges of the side panels and inwardly directed flanges along the lower edges of said slant panels, said flanges adapted to enter into said channels in response to swinging movement of said slant panels around their back edges.

12. A cargo box as in claim 11 including gaskets clamped between said flanges and walls of said channel forming means.

i3. A cargo box as in claim l2 in which said flanges and said channel walls are of sinuous cross-sectional shape to form respective pairs of gasket pockets when said slant wall is in position, and respective pairs of gaskets in said pockets.

ld. A cargo box as in claim l in which said clamping means each comprises means forming an outwardly opening channel along a side edge of the top panel, a downwardly extending flange along the corresponding edge of a side panel and a gasket clamped between said flange and a wall of said channel.

l5. A cargo box as in claim l including heat-insulating seals along adjacent edges of said base and said door and said panels.

lo. A cargo box as in claim l in which said releasable means comprises a latch at the front edge of said top panel, means mounting said latch on said top panel for movement between an open position and a closed position and interengageable means on said latch and on said door for clamping said door to said top panel.

i7. A cargo box as in claim i6 in which said clamping means comprise interengageable cam surfaces on said latch and on said door.

lid. A cargo box as in claim i7 including a sealing gasket between said door and said top panel.

i9. ln a refrigerated cargo box a door comprising a body of insulating material, said body having a rectangular lower portion and a trapezoidal upper portion, means carried by said body forming an outwardly directed tongue running along the bottom edge of the body, and means carried by said body forming a locking cam surface running around the remainder of the periphery of said body, said cam surface forming means providing a recess at the inner side of said panel running around the remainder of said periphery and a sealing gasket located in said recess.

20. A door as in claim i9 including heat insulation positioned around the inside of said body vadjacent the periphery thereof.

2l. ln a refrigerated cargo box a side panel comprising a generally rectangular body of insulating material, means forming a single inwardly directed tongue running along the bottom edge of said body, means forming respective outwardly directed single tongues running along the side edges of said body and means forming an outwardly opening channel along the upper edge of said body.

22. A side panel as in claim 2l in which said channel forming means provides an outer wall having a sinuous crosssectional shape and a gasket in said channel.

23. A side panel as in claim 22 including heat insulation positioned along the top and bottom edges of said body.

24. A side panel as in claim 21 including a latch provided with a cam surface and means mounting said latch for pivotal movement at the front edge ofsaid body.

25. ln a refrigerated cargo box, a back panel comprising a body of insulating material, said body having a generally rectangular lower portion and a trapezoidal upper portion, means carried by said body forming an outwardly directed tongue running along the lower edge of the panel, means carried by said body forming a dovetail groove running around the remainder of the periphery of the panel and a heatinsulating seal running around the periphery of said body.

2&6. ln a refrigerated cargo box, a slant roof panel comprising a generally rectangular body of insulating material, means forming an outwardly directed tongue along the back edge of said body and means forming respective inwardly directed flanges running along and spaced from the side edges of said body, said flanges having a sinuous cross-sectional shape and gaskets disposed between said flanges and said side edges.

27. A slant panel as in claim 26 including a latch formed with a cam surface and means mounting said latch for pivotal movement at the front edge ofthe body.

2d. ln a refrigerated cargo box a top panel comprising a rectangular body of insulating material, means forming an inwardly directed tongue along the rear edge of said body and means forming respective outwardly opening channels along the side edges of said body, said channels having arcuate outer sides and gaskets located in said channels.

29. A top panel as in claim 28 including a'latch having a cam surface and means mounting said latch for pivotal movement at the front edge of said body.

3ft. A refrigerated cargo box including in combination, a rectangular base, means forming a dovetail groove in the upper surface of said base around the periphery thereof, a back panel having a generally rectangular lower portion and a trapezoidal upper portion, means forming an outwardly directed tongue along the bottom edge of said back panel, said tongue located in said base groove, rneans forming a dovetail groove in the inner surface of said back panel around the remainder of the periphery thereof, respective generally rectangular side panels, means forming an inwardly directed tongue along the bottom edge of each of said side panels, said side panel bottom edge tongues located in the sides of said base groove, means forming outwardly directed tongues along the respective back edges of said side panels, said side `panel back edge tongues located in the vertical extents of said back panel groove, means forming outwardly opening channels along the top edgesof the respective side panels, respective generally rectangular slant top panels, means forming a respective upwardly directed tongue alonggthe back edge of each of said slant panels, said slant panel back edge tongues located in said back panel groove, means forming respective inwardly directed first and second flanges spaced from and along the upper and lower side edges of each of said slant panels, said lower edge flanges being received in said side panel channels, gaskets in said channels between said flanges and walls of said channels, a generally rectangular top panel', means forming a downwardly directed tongue extending along the back edge of said back panel, said top panel back edge tongue being disposed in the back panel groove, means forming respective outwardly opening channels along the side edges of the top panel, said top panel channels receiving said slant panel'upper edge flanges, gaskets located in the top panel channels between walls thereof and said slant panel flanges, a door having a rectangular lower portion and a trapezoidal upper portion, means formingI an inwardly directed tongue along the loweredge of said door, said `doory lower edge tongue located in said base groove, and means extending around the remainder of the periphery of the door for releasably clamping said door in position.

3l. A refrigerated cargo box as in claim 30 in which said clamping means comprises respective latches each providing a cam surface, means mounting said latches respectively on the front edges of the side panels and slant panels and top panels, and means on said door providing cam surfaces for cooperating with said latch cam surfaces.

32. A readily disassembled cargo box including in combination, a base having a rectangular configuration, a back panel, respective side panels, a front panel, a roof, and readily releasable means for connecting said back paneland said front panel and said side panels and said roof and said base to form said box, said releasable means comprising interengageable means running along the bottoms of said back panel and said side panels and said front panels and around the perimeter of said base, said interengageable means comprising means forming a dovetail groove along each of the front and back and sides of said base adjacent the edges thereof, each of said dovetail grooves having a mouth and oppositely directed groove portions extending from said mouth, and respective single tongues extending along-the bottom edges of each of said front and back and side panels, each of said tongues being adapted to be inserted in one of said grooves through said mouth upon movement of the panel edge toward the base and to engage in one of said groove portions upon rotation of the panel relative to the base.

33. A cargo box as in claim 32 in which said dovetail grooves run respectively along the sides of said base adjacent the edge thereof, said tongues comprising respective inwardly directed curved tongues along the bottoms of said side panels and respective outwardly directed curved tongues along the bottoms of the front and back panels.

34. A cargo box as in claim 32 in which said dovetail grooves run rpectively along the sides of said base adjacent the edge thereof, said tongues comprising respective curved tongues along the bottoms of said side panels, said side panel tongue being oriented in one sense with reference to said base, and a curved tongue running along the bottom of said back panel, said back panel tongue being oriented in the opposite sense with reference to said base.

35. A cargo box including in combination, a generally rectangular base, a pair of generally rectangular side panels, a pair of generally rectangular end panels, and a generally rectangular top panel, rst readily disengageable interlocking elements respectively unitary with and extending along the bottom edges of each of said side and end panels substantially from end-to-end thereof and unitary with and extending around the periphery of said base for connecting said side and end panels to said base, second readily disengagcable interlocking elements respectively unitary with and extending along the front and rear edges of said side panels substantially from top to bottom thereof` and unitary with and extending along the side edges of said end panels substantially from top to bottom thereof for connecting said side panels to said end l2 panels, and means connectingrsaid top panel to said side and end panels, said second elements respectively comprising outwardly directed tongues along the end edges of said side panels and inwardly directed tongues along the side edges of said end panels.

36. ln a knock down container, an assembly including a first panel, a second panel, said panels having respective generally straight edges along which said panels are to be joined, a first elongated angle member having respective portions generally at right angles to each other, means securing said first angle member to said first panel with one of said portions spaced from and generally parallel to the straight edge of said member, a second elongated angle member having respective portions generally at right angles to each other and means securing said second angle member to said second panel with one of the portions of the second member spaced from and generally parallel to a side of said second panel adjacent its straight edge, said spaced portions adapted to interengage to assembled said panels along said edges in response to relative sliding movement of said panels.

37. An assembly as in claim 36 including respective gaskets disposed in the space between said spaced member portions and the associated panels. 

1. A readily disassembled cargo box including in combination, a base having a rectangular configuration, a back panel having a Rectangular lower portion and a generally trapezoidal upper portion, respective rectangular side panels, respective rectangular slant roof panels, a rectangular central roof panel, a door having a rectangular lower portion and a trapezoidal upper portion and readily releasable means for connecting said back and side panels and said roof panels and said door to form said box, said releasable means comprising means forming respective clamping means along adjacent edges of said top panel and of said slant panels, said clamping means adapted to engage in response to swinging movement of said top panel about its back edge.
 2. A cargo box as in claim 1 in which said panels and said door are formed of insulating material.
 3. A cargo box as in claim 1 in which said releasable means comprises interengageable means running along the bottoms of said side panels and along the corresponding edges of said base, said interengageable means comprising dovetail grooves and tongues located in said grooves.
 4. A cargo box as in claim 3 in which said dovetail grooves are in said base and in which said tongues are inwardly directed tongues on the bottoms of said side panels.
 5. A cargo box as in claim 1 in which said readily releasable means comprise interengageable means running along the bottom of said back panel and said door and along corresponding edges of said base, said interengageable means comprising dovetail grooves and tongues located in said grooves.
 6. A cargo box as in claim 5 in which said dovetail grooves are in said base and wherein said tongues are outwardly directed tongues on said back panel and door.
 7. A cargo box as in claim 1 in which said readily releasable means comprises means forming a dovetail groove in the upper surface of said base running around the periphery thereof, respective inwardly directed tongues along the bottom edges of said side panels located in corresponding portions of said groove and respective outwardly directed tongues along the bottom edges of said back panel and said door.
 8. A cargo box as in claim 1 in which said releasable means comprises interengageable tongue and groove forming means along the rear edges of said side panels and along the vertical edges of said back panel.
 9. A cargo box as in claim 1 in which said releasable means comprises means forming a dovetail groove adjacent the upper edge of said back panel, respective upwardly directed tongues along the edges of said slant panel located in said groove and a downwardly directed tongue at the rear edge of said central top panel, said tongues located in said grooves.
 10. A cargo box as in claim 1 in which said releasable means comprises clamping means extending along adjacent edges of the side panels and slant roof panels.
 11. A cargo box as in claim 10 in which said clamping means comprises means forming outwardly opening channels along the upper edges of the side panels and inwardly directed flanges along the lower edges of said slant panels, said flanges adapted to enter into said channels in response to swinging movement of said slant panels around their back edges.
 12. A cargo box as in claim 11 including gaskets clamped between said flanges and walls of said channel forming means.
 13. A cargo box as in claim 12 in which said flanges and said channel walls are of sinuous cross-sectional shape to form respective pairs of gasket pockets when said slant wall is in position, and respective pairs of gaskets in said pockets.
 14. A cargo box as in claim 1 in which said clamping means each comprises means forming an outwardly opening channel along a side edge of the top panel, a downwardly extending flange along the corresponding edge of a side panel and a gasket clamped between said flange and a wall of said channel.
 15. A cargo box as in claim 1 including heat-insulating seals along adjacent edges of said base and said door and said panels.
 16. A cargo box as in claim 1 in which said releasable means comprises a latch at the fronT edge of said top panel, means mounting said latch on said top panel for movement between an open position and a closed position and interengageable means on said latch and on said door for clamping said door to said top panel.
 17. A cargo box as in claim 16 in which said clamping means comprise interengageable cam surfaces on said latch and on said door.
 18. A cargo box as in claim 17 including a sealing gasket between said door and said top panel.
 19. In a refrigerated cargo box a door comprising a body of insulating material, said body having a rectangular lower portion and a trapezoidal upper portion, means carried by said body forming an outwardly directed tongue running along the bottom edge of the body, and means carried by said body forming a locking cam surface running around the remainder of the periphery of said body, said cam surface forming means providing a recess at the inner side of said panel running around the remainder of said periphery and a sealing gasket located in said recess.
 20. A door as in claim 19 including heat insulation positioned around the inside of said body adjacent the periphery thereof.
 21. In a refrigerated cargo box a side panel comprising a generally rectangular body of insulating material, means forming a single inwardly directed tongue running along the bottom edge of said body, means forming respective outwardly directed single tongues running along the side edges of said body and means forming an outwardly opening channel along the upper edge of said body.
 22. A side panel as in claim 21 in which said channel forming means provides an outer wall having a sinuous cross-sectional shape and a gasket in said channel.
 23. A side panel as in claim 22 including heat insulation positioned along the top and bottom edges of said body.
 24. A side panel as in claim 21 including a latch provided with a cam surface and means mounting said latch for pivotal movement at the front edge of said body.
 25. In a refrigerated cargo box, a back panel comprising a body of insulating material, said body having a generally rectangular lower portion and a trapezoidal upper portion, means carried by said body forming an outwardly directed tongue running along the lower edge of the panel, means carried by said body forming a dovetail groove running around the remainder of the periphery of the panel and a heat-insulating seal running around the periphery of said body.
 26. In a refrigerated cargo box, a slant roof panel comprising a generally rectangular body of insulating material, means forming an outwardly directed tongue along the back edge of said body and means forming respective inwardly directed flanges running along and spaced from the side edges of said body, said flanges having a sinuous cross-sectional shape and gaskets disposed between said flanges and said side edges.
 27. A slant panel as in claim 26 including a latch formed with a cam surface and means mounting said latch for pivotal movement at the front edge of the body.
 28. In a refrigerated cargo box a top panel comprising a rectangular body of insulating material, means forming an inwardly directed tongue along the rear edge of said body and means forming respective outwardly opening channels along the side edges of said body, said channels having arcuate outer sides and gaskets located in said channels.
 29. A top panel as in claim 28 including a latch having a cam surface and means mounting said latch for pivotal movement at the front edge of said body.
 30. A refrigerated cargo box including in combination, a rectangular base, means forming a dovetail groove in the upper surface of said base around the periphery thereof, a back panel having a generally rectangular lower portion and a trapezoidal upper portion, means forming an outwardly directed tongue along the bottom edge of said back panel, said tongue located in said base groove, means forming a dovetail groove in the inner surface of said back panel around the remainder of the perIphery thereof, respective generally rectangular side panels, means forming an inwardly directed tongue along the bottom edge of each of said side panels, said side panel bottom edge tongues located in the sides of said base groove, means forming outwardly directed tongues along the respective back edges of said side panels, said side panel back edge tongues located in the vertical extents of said back panel groove, means forming outwardly opening channels along the top edges of the respective side panels, respective generally rectangular slant top panels, means forming a respective upwardly directed tongue along the back edge of each of said slant panels, said slant panel back edge tongues located in said back panel groove, means forming respective inwardly directed first and second flanges spaced from and along the upper and lower side edges of each of said slant panels, said lower edge flanges being received in said side panel channels, gaskets in said channels between said flanges and walls of said channels, a generally rectangular top panel, means forming a downwardly directed tongue extending along the back edge of said back panel, said top panel back edge tongue being disposed in the back panel groove, means forming respective outwardly opening channels along the side edges of the top panel, said top panel channels receiving said slant panel upper edge flanges, gaskets located in the top panel channels between walls thereof and said slant panel flanges, a door having a rectangular lower portion and a trapezoidal upper portion, means forming an inwardly directed tongue along the lower edge of said door, said door lower edge tongue located in said base groove, and means extending around the remainder of the periphery of the door for releasably clamping said door in position.
 31. A refrigerated cargo box as in claim 30 in which said clamping means comprises respective latches each providing a cam surface, means mounting said latches respectively on the front edges of the side panels and slant panels and top panels, and means on said door providing cam surfaces for cooperating with said latch cam surfaces.
 32. A readily disassembled cargo box including in combination, a base having a rectangular configuration, a back panel, respective side panels, a front panel, a roof, and readily releasable means for connecting said back panel and said front panel and said side panels and said roof and said base to form said box, said releasable means comprising interengageable means running along the bottoms of said back panel and said side panels and said front panels and around the perimeter of said base, said interengageable means comprising means forming a dovetail groove along each of the front and back and sides of said base adjacent the edges thereof, each of said dovetail grooves having a mouth and oppositely directed groove portions extending from said mouth, and respective single tongues extending along the bottom edges of each of said front and back and side panels, each of said tongues being adapted to be inserted in one of said grooves through said mouth upon movement of the panel edge toward the base and to engage in one of said groove portions upon rotation of the panel relative to the base.
 33. A cargo box as in claim 32 in which said dovetail grooves run respectively along the sides of said base adjacent the edge thereof, said tongues comprising respective inwardly directed curved tongues along the bottoms of said side panels and respective outwardly directed curved tongues along the bottoms of the front and back panels.
 34. A cargo box as in claim 32 in which said dovetail grooves run respectively along the sides of said base adjacent the edge thereof, said tongues comprising respective curved tongues along the bottoms of said side panels, said side panel tongue being oriented in one sense with reference to said base, and a curved tongue running along the bottom of said back panel, said back panel tongue being oriented in the opposite sense with refErence to said base.
 35. A cargo box including in combination, a generally rectangular base, a pair of generally rectangular side panels, a pair of generally rectangular end panels, and a generally rectangular top panel, first readily disengageable interlocking elements respectively unitary with and extending along the bottom edges of each of said side and end panels substantially from end-to-end thereof and unitary with and extending around the periphery of said base for connecting said side and end panels to said base, second readily disengageable interlocking elements respectively unitary with and extending along the front and rear edges of said side panels substantially from top to bottom thereof and unitary with and extending along the side edges of said end panels substantially from top to bottom thereof for connecting said side panels to said end panels, and means connecting said top panel to said side and end panels, said second elements respectively comprising outwardly directed tongues along the end edges of said side panels and inwardly directed tongues along the side edges of said end panels.
 36. In a knock down container, an assembly including a first panel, a second panel, said panels having respective generally straight edges along which said panels are to be joined, a first elongated angle member having respective portions generally at right angles to each other, means securing said first angle member to said first panel with one of said portions spaced from and generally parallel to the straight edge of said member, a second elongated angle member having respective portions generally at right angles to each other and means securing said second angle member to said second panel with one of the portions of the second member spaced from and generally parallel to a side of said second panel adjacent its straight edge, said spaced portions adapted to interengage to assembled said panels along said edges in response to relative sliding movement of said panels.
 37. An assembly as in claim 36 including respective gaskets disposed in the space between said spaced member portions and the associated panels. 